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C G Lobe

Publications and source records attributed to C G Lobe.

25 records · Page 2Linked to original sources
PubMed1988

A molecular-genetic analysis of cytotoxic T lymphocyte function.

Two genes that are specifically expressed in T cells with cytolytic activity were isolated from a CTL cDNA library by differential screening. Both appear to encode serine proteases, thus suggesting a cascade mechanism, similar to complement, in activated CTL. Both CTL-specific proteases have a number of unusual structural features that suggest that they will have novel substrate specificities. One of the proteins (CCPI) has been oriented to the granules found in the cytoplasm of CTL. Taken together, these data strongly suggest that these molecules play an important role in target-cell lysis by CTL. Furthermore, we believe that the detailed molecular knowledge being accumulated through these studies may lead to the development of innovative forms of immunotherapy.

Amino Acid Sequence↗
PubMed1986

Novel serine proteases encoded by two cytotoxic T lymphocyte-specific genes.

Genes that are expressed exclusively in cytotoxic T cells should encode proteins that are essential for target cell lysis in cell-mediated immune responses. The sequences of two cytotoxic T lymphocyte-specific complementary DNA's (cDNA's) suggest that the two genes encode serine proteases. A full-length cDNA corresponding to one of the genes was isolated and sequenced. The predicted protein resembles serine proteases in that it includes all the residues that form the catalytic triad of the active site of serine proteases. Moreover, it has sequence characteristics thought to occur only in rat mast cell protease type II. These results are in accord with the view that a protease cascade plays a key role in cytotoxic T-cell activation.

Animals↗
PubMed1986

Translocation of murine interleukin 2 into microsomes during translation in a cell-free system.

Interleukin 2 (IL2) is a lymphokine which stimulates the growth of T lymphocytes. Although IL2 mRNA is translated into biologically active IL2 relatively efficiently in microinjected Xenopus laevis oocytes, it has been difficult to establish reproducible cell-free translation systems for this lymphokine. Such systems would be useful for the analysis of translational and post-translational events. In this paper, we show that a wheat germ extract will translate IL2 mRNA into biologically active murine IL2, most of which is translocated into dog pancreas microsomes when these are present. Translocation occurs only during translation, but wheat germ extracts translate IL2 mRNA whether microsomes are present or not. Surprisingly, reticulocyte lysates do not readily translate IL2 mRNA, and strongly inhibit its translation in wheat germ extracts. This inhibition can be partially alleviated by adding dog pancreas microsomes to the system. The inhibition seen with reticulocyte lysate may be attributable to the action of the signal recognition particle, which binds nascent secretory proteins, and blocks their further translation in the absence of the docking protein present in microsomes.

Animals↗
PubMed1986

Cloning of two genes that are specifically expressed in activated cytotoxic T lymphocytes.

The intracellular events leading to cytotoxic T-lymphocyte (CTL) activation and the molecular mechanism of target-cell lysis remain largely unknown. Differential hybridization analysis of a library constructed from a cloned CTL line was used to identify sequences specifically expressed in CTL. Two clones were selected for extensive analysis. No evidence for expression of their mRNAs was found in helper T-cell lines, thymocytes, lipopolysaccharide-activated B cells, interferon-treated natural killer cells, and a number of nonlymphoid cells. Blot-hybridization analysis of CTL mRNA revealed that one clone detected a single 900-nucleotide mRNA, whereas the other hybridized to two mRNAs of 900 and 1200 nucleotides, respectively. The maximum expression of these mRNAs precedes the peak of cytotoxicity in an in vitro allogeneic or mitogen-induced cytotoxic response by 24 hr; thus, they both fulfill the primary prerequisite for genes encoding proteins that are important in either CTL activation or in the lytic process itself.

Animals↗
PubMed1985

Complete 1H assignments of the non-exchangeable protons of the non self-complementary heptadeoxyribonucleotide d[(GTCGTCA).(TGACGAC)] and its component strands by high field NMR.

The non self complementary heptadeoxyribonucleotides d(GTCGTCA) and d(TGACGAC) were synthesized by the phosphotriester method. While complete 1H-NMR assignments of the former were obtained by a combination of one and two-dimensional techniques at room temperature, extensive stacking of the latter under these conditions dictated analysis at 50 degrees C when the lines were sharply resolved. The duplex form of the annealed strands under the conditions of the 1H-NMR experiment was established independently of the NMR evidence by 32P end labeling with T4 polynucleotide kinase followed by butt end joining using the absolute specificity of T4 ligase for double strand DNA. Analysis of the resulting ladder of polymers was performed using gel electrophoresis and autoradiography. Complete 1H-NMR assignments of the non-exchangeable protons in the self complementary heptamer was achieved. The assignments were confirmed using NOE differences, and two-dimensional COSY, and HH-INADEQUATE experiments at 400 and 500 MHz. The assignments are in accord with a conformation for the heptamer belonging to the B family of structures.

Base Sequence↗
PubMedDate not supplied

Z/EG, a double reporter mouse line that expresses enhanced green fluorescent protein upon Cre-mediated excision.

The Cre/loxP system has become an important tool in designing postintegrational switch mechanisms for transgenes in mice. The power and spectrum of application of this system depends on transgenic mouse lines that provide Cre recombinase activity with a defined cell type-, tissue-, or developmental stage-specificity. We have developed a novel mouse line that acts as a Cre reporter. The mice, designated Z/EG (lacZ/EGFP), express lacZ throughout embryonic development and adult stages. Cre excision, however, removes the lacZ gene, which activates expression of the second reporter, enhanced green fluorescent protein. We have found that the double-reporter Z/EG line is able to indicate the occurrence of Cre excision from early embryonic to adult lineages. The advantage of the Z/EG line is that Cre-mediated excision can be monitored in live samples and that live cells with Cre-mediated excision can be isolated using a single-step FACS. It will be a valuable reagent for the increasing number of investigators taking advantage of the powerful tools provided by the Cre/loxP site-specific recombinase system.

Alkaline Phosphatase↗